1. Field of the Invention
The present invention relates generally to a replaceable ink cartridge, and more particularly to a replaceable ink cartridge to be replaceably connected to a recording head into which ink is supplied therefrom. Also, the present invention relates to a seal structure to seal openings of the replaceable ink cartridge, and more particularly to a seal structure with improved properties of sealing an ink outlet and en air communicating port of the replaceable ink cartridge.
2. Description of the Related Art
Heretofore, various kinds of recording apparatus for performing an image formation on a recording medium such as a sheet of recording paper, a piece of fabric, and a sheet of plastic material e.g., one used for overhead projector (generally called as a OHP sheet) have been proposed as in the form of mounting a recording head in the type of wire dot matrix recording, thermal recording, thermal transfer recording, ink jet recording, or the like. Among the conventional recording methods, the ink jet recording apparatus having a recording head in the type of performing ink jet method has been used as various kinds of recording (printing) system so as to being commercially available. In this case, the ink jet recording head should be constructed to meet the user's demands of the mechanism, configuration, application and the like of the individual system.
The ink jet recording apparatus generally comprises: a carriage for carrying a recording means (i.e., a recording head) and an ink tank; a transfer means for transferring a recording medium (e.g., a sheet of recording paper); and a control means for controlling the drive of these means. In the ink jet recording apparatus, the ink jet recording head performs its serial scanning movement (i.e., the head scans over a surface of the recording head sequentially) along the direction (main-scanning direction) perpendicular to the direction (sub-scanning direction) of transmitting the recording medium for ejecting ink droplets from a plurality of ejection orifices, while the recording medium is intermittently shifted at a distance corresponding to a recording width of the recording medium. The process of ink jet recording is characterized by ejecting ink droplets on the recording medium in accordance with the recording signals, so that it has been widely applied in various systems as a noiseless recording process with an inexpensive running cost. By using the recording head comprising a plurality of ink-ejecting nozzles linearly arranged in the sub-scanning direction, an image having a width thereof corresponding to the number of the nozzles can be recorded by a single scanning movement of the recording head. Consequently, the high-speed recording movement can be attained.
In the case of an ink jet recording apparatus adaptable to a full color image formation, furthermore, each of recording heads corresponding to several colors elects a color ink droplet, so that each of all colors is obtainable by placing ink droplets one upon another. Generally, three or four recording heads with ink tanks corresponding to three primary colors of yellow (Y), magenta (M), and cyan (C) and a color of black (B) are required for recording the color image. In recent years, an ink jet recording apparatus that carries recording heads corresponding to these three or four colors has teen practically used for full color image formation.
Furthermore, the ink jet recording apparatus as mentioned above can be constructed with a relatively easily manner so as to fit to the process of recording a larger sized image such as a A1 sized one. For recording a A1 sized color image, the recording apparatus has been practically provided so as to be able to connect with an image reader for making a copy of original. This kind or the apparatus is provided as, for example a plotter such as an output printer of computer-aided design (CAD) system. On the other hand, diversified demands of re-cording images on various kinds of recording medium have been increased. For example, a demand of recording an image on the OHP sheet by the ink jet recording apparatus has been increased because the OHP sheet can be used in a system of projecting the image for giving a presentation in a lecture, a conference, a meeting, or the like. For a request to the above demand, another kind of the ink jet recording apparatus has been developed and provided in practical use. That is, this recording apparatus is constructed to perform an excellent image formation without depending on a result of selecting and using one of various recording media having different properties of absorbing ink.
Accordingly, the aforementioned ink jet recording apparatus has been regarded as an excellent recording means and required as useful in widely distributed industrial fields, for example apparel and textile industries. Furthermore, there is a demand of providing a further improved qualities of images in these fields.
In an ink jet recording head (hereafter, also referred as a recording head) to be installed on the ink jet recording apparatus, by the way, means for generating energy required for ejecting ink can be exemplified by a recording element of the type having an electromechanical transducer such as a piezo element or the like used therefor, and a recording element of the type adapted to heat liquid with the aid of an electrothermal converting element including a heat generating resistor.
Among various kinds of recording heads, a recording head of the type adapted to eject liquid therefrom by utilizing thermal energy makes it possible to perform a recording operation with a high degree of resolution because a plurality of liquid ejection ports can be arranged on the recording head at a high density.
By the way, there are several types of the characteristic configuration for supplying ink to the aforementioned recording head, such as one connecting the recording head with the ink tank by means of a flexible tube, one directly connecting them as an integrated unit to be replaceably installed on the recording apparatus, and one removable connecting them each other. Especially in the recent years, the number of the recording apparatuses using the type of removable connecting the recording head and the ink tank to form a unit has been increased.
An replaceable ink cartridge to be removably connected with the recording head to form such unit comprises a main body made of a plastic material or the like on which an ink outlet and an air communicating port are formed. The ink outlet is for supplying an ink to the recording head while the air communicating port is for communicating with the open air. For the purpose of its physical distribution, these openings are sealed up with a seal member after filling the body with ink to prevent an ink leakage from the body under the changeable environmental conditions such as, a physical vibration, a surrounding temperature and an atmospheric pressure. At the time of using the ink cartridge, the seal member is peeled off. At this moment, furthermore, the seal member receives a tension and a shear stress, so that the seal member should be made of a proof material with respect to such forces, such as a flexible material, for example an aluminum laminate resin formed by laminating an aluminum thin film and a resin material.
By the way, it is noted that the ink outlet and the air communicating port are sealed by a single piece of the seal member from the point of view that the seal member should be easily peeled off from these openings.
Mostly, the replaceable ink cartridge as described above is constructed so as to keep ink in an ink absorber being installed in the ink cartridge's body. In this case, in addition, the ink absorber occupies a predetermined space of an interior of the body to make a concentration of ink around the ink outlet for easily providing the ink to the recording head and also to avoid a concentration of ink to the air communicating port.
In some instances, conventionally, the ink outlet can be sealed off at first when the user pulls an end of the seal member toward a certain direction. When the ink outlet is opened at first prior to open the air communicating port, a certain amount ot ink scatters in all directions at an inner pressure of the cartridge which is higher than an atmospheric pressure by a change in temperature and atmospheric condition. As a consequence, the scattered ink stains the user's hands and clothes. Furthermore, in the case that a gaseous body such as air is sealed up hermetically with ink in the ink cartridge, the above problem is more serious because there is the possibility that ink scatters from the ink outlet in all directions at an increased inner pressure of the cartridge occurred by swelling the gaseous body.